I apologize if this is a common DocBook settings question but after looking into several places I cannot figure out how to have the images scaled so that they do not cut off (at the right) when producing pdf. With HTML transformation, we can manage using the htmlstyle.css I am wondering if we can do something similar for pdf.

I looked into pdf parameters and did not find anything that can help with this.

If you are editing the XML document in the Author visual editing mode, click the image then open the "Attributes" view (main menu -> Window->Show View) and set the attributes there. Or use ALT-ENTER to open the in-place attributes editor. Or switch to the "Text" editing mode and set the attributes there.